Add Binder to BootstrapContext

Update `ConfigDataEnvironment` so that it adds the initial `Binder`
to the `BootstrapContext` for `Bootstrappers` to use.

Closes gh-23401

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/context/config/ConfigDataEnvironment.java

@@ -25,6 +25,7 @@ import java.util.Set;
 
 import org.apache.commons.logging.Log;
 
+import org.springframework.boot.BootstrapRegistry.InstanceSupplier;
 import org.springframework.boot.ConfigurableBootstrapContext;
 import org.springframework.boot.DefaultPropertiesPropertySource;
 import org.springframework.boot.context.config.ConfigDataEnvironmentContributors.BinderOption;
@@ -198,8 +199,12 @@ class ConfigDataEnvironment {
 	 */
 	void processAndApply() {
 		ConfigDataImporter importer = new ConfigDataImporter(this.resolvers, this.loaders);
+		this.bootstrapContext.register(Binder.class, InstanceSupplier
+				.from(() -> this.contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE)));
 		ConfigDataEnvironmentContributors contributors = processInitial(this.contributors, importer);
-		ConfigDataActivationContext activationContext = createActivationContext(contributors);
+		Binder initialBinder = contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
+		this.bootstrapContext.register(Binder.class, InstanceSupplier.of(initialBinder));
+		ConfigDataActivationContext activationContext = createActivationContext(initialBinder);
 		contributors = processWithoutProfiles(contributors, importer, activationContext);
 		activationContext = withProfiles(contributors, activationContext);
 		contributors = processWithProfiles(contributors, importer, activationContext);
@@ -212,11 +217,10 @@ class ConfigDataEnvironment {
 		return contributors.withProcessedImports(importer, null);
 	}
 
-	private ConfigDataActivationContext createActivationContext(ConfigDataEnvironmentContributors contributors) {
+	private ConfigDataActivationContext createActivationContext(Binder initialBinder) {
 		this.logger.trace("Creating config data activation context from initial contributions");
-		Binder binder = contributors.getBinder(null, BinderOption.FAIL_ON_BIND_TO_INACTIVE_SOURCE);
 		try {
-			return new ConfigDataActivationContext(this.environment, binder);
+			return new ConfigDataActivationContext(this.environment, initialBinder);
 		}
 		catch (BindException ex) {
 			if (ex.getCause() instanceof InactiveConfigDataAccessException) {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/ConfigDataEnvironmentPostProcessorBootstrapContextIntegrationTests.java

@@ -34,7 +34,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  *
  * @author Phillip Webb
  */
-class ConfigDataEnvironmentPostProcessorBootstrapRegistryIntegrationTests {
+class ConfigDataEnvironmentPostProcessorBootstrapContextIntegrationTests {
 
 	private SpringApplication application;
 
@@ -50,6 +50,7 @@ class ConfigDataEnvironmentPostProcessorBootstrapRegistryIntegrationTests {
 				.run("--spring.config.import=classpath:application-bootstrap-registry-integration-tests.properties")) {
 			LoaderHelper bean = context.getBean(TestConfigDataBootstrap.LoaderHelper.class);
 			assertThat(bean).isNotNull();
+			assertThat(bean.getBound()).isEqualTo("igotbound");
 			assertThat(bean.getLocation().getResolverHelper().getLocation()).isEqualTo("testbootstrap:test");
 		}
 	}

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/context/config/TestConfigDataBootstrap.java

@@ -19,15 +19,17 @@ package org.springframework.boot.context.config;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.List;
+import java.util.function.Supplier;
 
 import org.springframework.boot.BootstrapContextClosedEvent;
 import org.springframework.boot.BootstrapRegistry.InstanceSupplier;
+import org.springframework.boot.context.properties.bind.Binder;
 import org.springframework.context.ApplicationListener;
 import org.springframework.core.env.MapPropertySource;
 
 /**
  * Test classes used with
- * {@link ConfigDataEnvironmentPostProcessorBootstrapRegistryIntegrationTests} to show how
+ * {@link ConfigDataEnvironmentPostProcessorBootstrapContextIntegrationTests} to show how
  * a bootstrap registry can be used. This example will create helper instances during
  * result and load. It also shows how the helper can ultimately be registered as a bean.
  *
@@ -57,7 +59,7 @@ class TestConfigDataBootstrap {
 		@Override
 		public ConfigData load(ConfigDataLoaderContext context, Location location) throws IOException {
 			context.getBootstrapContext().registerIfAbsent(LoaderHelper.class,
-					InstanceSupplier.from(() -> new LoaderHelper(location)));
+					(bootstrapContext) -> new LoaderHelper(location, () -> bootstrapContext.get(Binder.class)));
 			LoaderHelper helper = context.getBootstrapContext().get(LoaderHelper.class);
 			context.getBootstrapContext().addCloseListener(helper);
 			return new ConfigData(
@@ -103,14 +105,21 @@ class TestConfigDataBootstrap {
 
 		private final Location location;
 
-		LoaderHelper(Location location) {
+		private final Supplier<Binder> binder;
+
+		LoaderHelper(Location location, Supplier<Binder> binder) {
 			this.location = location;
+			this.binder = binder;
 		}
 
 		Location getLocation() {
 			return this.location;
 		}
 
+		String getBound() {
+			return this.binder.get().bind("myprop", String.class).orElse(null);
+		}
+
 		@Override
 		public void onApplicationEvent(BootstrapContextClosedEvent event) {
 			event.getApplicationContext().getBeanFactory().registerSingleton("loaderHelper", this);

spring-boot-project/spring-boot/src/test/resources/application-bootstrap-registry-integration-tests.properties

@@ -1 +1,2 @@
 spring.config.import=testbootstrap:test
+myprop=igotbound